It will be appreciated by those skilled in the art, that devices have heretofore been known for mixing liquids with water. Such devices typically provide a dispensing apparatus or assembly which is attached into the flow path of water discharged from a showerhead or faucet. Certain devices also include dispensing reservoirs of particular designs which are compatible with the dispenser itself to mix the liquid with the water. As an example, U.S. Pat. No. 4,358,056 discloses a shower dispenser which includes a reservoir assembly for holding a liquid and a mixer coupling for connecting a shower water supply and liquid contained within the reservoir. The reservoir assembly includes a specially designed housing having a first and second reservoir or containers which can hold liquid to be mixed into the water. Moreover, this device includes a check valve ball which is designed to move against a valve seat to prevent backward flow of liquid which might otherwise be occasioned by the flow of pressurized water into the venturi. Other known prior art devices are disclosed in the following U.S. Pat. Nos.: 2,690,717; 3,333,601; 4,121,773; 4,218,013; 4,607,703; 4,651,930; and 4,697,610.
While known prior art devices have addressed the problem of providing a device for mixing liquid into shower water, certain disadvantages remain.
Accordingly, it is an object of the present invention to provide an inexpensive coupling which will mix liquid with the shower water and which has a minimal number of moving parts which can wear out.
Another object of the present invention is to provide such a coupling which prevents backward flow of water into the liquid dispensing reservoir without the need of an additional check valve.
Yet another object of the present invention is to provide such a coupling for mixing liquids with the shower water which can be readily installed and which incorporates in the preferred embodiment an automatic shut-off feature which vents the venturi vacuum to atmosphere when the flow of water through showerhead is terminated.
Also, it is an object of the present invention to provide such a coupling for mixing liquid and shower water which can be readily actuated by the simple depression of a vacuum actuator button.